Lync Server does not support single-labeled domains. For example, a forest with a root domain named contoso.local is supported, but a root domain named local is not supported. For details, see Microsoft Knowledge Base article 300684, “Information about configuring Windows for domains with single-label DNS names,” at http://go.microsoft.com/fwlink/p/?linkid=3052&kbid=300684.

Note:

Lync Server 2010 does not support renaming domains. If you need to rename a domain where Lync Server is deployed, you need to first uninstall Lync Server, then rename the domain, and then reinstall Lync Server.